National Insect & Disease Risk and Hazard Mapping
The National Insect and Disease Risk Map (NIDRM) is a nationwide strategic assessment and database of the potential hazard for tree mortality due to major forest insects and diseases. The goal of NIDRM is to summarize landscape-level patterns of potential insect and disease activity to inform management and decision-making.
NIDRM is a forward-looking product that identifies risk over a 15-year period. Forest Health Protection aims to update NIDRM on an approximately 5-year cycle so that it reflects contemporary forest conditions and scientific understanding of tree hosts and forest insects and diseases.
NIDRM data can be used to:
Identify the potential impacts of insects and pathogens to private and public forests throughout the US over a forward looking 15 –year period.
Generate forest insect and pathogen risk maps at a scale useful for resource planning and management purposes (e.g., in National Forests and National Parks).
Inform strategic planning and ensure resources for forest pest prevention, suppression, and restoration reach priority areas.
Identify areas where hazardous fuels treatments coincide with risk for forest pest activity, much of which is density driven. Efficiencies will be gained by implementing active management to achieve multiple, combined resource objectives (e.g., fire and pest hazard mitigation).
Streamline environmental compliance (e.g., by making Categorial Exclusions available via the Healthy Forest Restoration Act).
In sum, decision-makers and insect and disease information users apply NIDRM to various planning needs when future-oriented information is necessary. In contrast, information users interested in past insect and disease activities should visit the FHP Insect and Disease Survey webpage for data and tools. Users who are interested in how forest conditions have changed over time may visit the Forest Inventory and Analysis webpage for data and tools.
The most recent NIDRM product is available below, as well as selected prior editions and associated products (assessment reports, pest and host maps, etc.).
How many “at risk” acres are identified in the most recent NIDRM?
The 2024 NIDRM identified more than 66.8 million forested acres in the conterminous US that are at risk for significant tree morality due to insects and diseases. This represents approximately 6.5% of US forests in the lower 48 states.What kinds of decisions can NIDRM inform?
NIDRM supports land managers, policy makers and others who need to identify and prioritize areas of concern. Because NIDRM is forward-looking, it supports proactive decisions and management actions that reduce insect and disease hazard. It is best applied to broad-scales (e.g., at the scale of a Forest Service Ranger District), where it can inform strategic planning to ensure resources for pest prevention, suppression, and restoration reach priority areas.Are there decisions for which other insect and disease information sources are more appropriate than NIDRM?
NIDRM is a forward-looking product that anticipates future insect and disease-driven mortality and live basal area loss. It is best applied to broad, landscape-scale planning and decision-making needs (e.g., identifying priority landscapes for management actions, completing NEPA compliance).For information users interested in past insect and disease activity, Insect and Disease Survey data are a more appropriate data source. Please visit the IDS webpage for more information.
Information for users who are interested in how forest conditions are changing over time, Forest Inventory and Analysis’ Nationwide Forest Inventory may be a more appropriate data source. Learn more by visiting: https://research.fs.usda.gov/programs/nfi
Can results of each NIDRM be directly compared with one another?
No, not at present. Each version of the risk map utilizes the best available science information to create the risk map. Methods, data, and models have improved over each iteration, which is beneficial for decision making, but limits user ability to directly compare each edition of the map.
2024 National Insect and Disease Risk Map
FHP completed a 2024-2038 risk map that addresses risk in the conterminous US. The main 2024 NIDRM product is the composite risk dataset; this product represents the integration of 172 individual insect and disease hazard models, all constructed within a common GIS-based, multi-criteria framework that can account for regional variations in forest health.
NIDRM defines risk, or more precisely hazard, as the expectation that 25 percent or more of the standing live basal area of trees greater than 1 inch in diameter will die over a 15-year time frame due to insects and diseases. The 2024 NIDRM identified more than 66.8 million forested acres in the conterminous US (6.4% of forested acres) that are at risk for significant tree morality due to insects and diseases.
The production of the 2024 NIDRM has been a highly collaborative process led by the Forest Service’s Forest Health Protection Program. For more information on data and models, see supporting documentation for the 2012 Risk Map, below, as the 2012 risk map used the same models, modelling tools, and model predictors (the 2024 product updated these using data reflecting current conditions).
2024 National Insect and Disease Risk Map Viewer
Interactive web map of the 2024 NIDRM
| 2024 NIDRM COMPOSITE MAPS |
|---|
| NIDRM Contiguous U.S. (8.5" x 11") (PDF, 6 MB) |
| NIDRM Region 1 (8.5" x 11") (PDF, 6 MB) |
| NIDRM Region 2 (8.5" x 11") (PDF, 8 MB) |
| NIDRM Region 3 (8.5" x 11") (PDF, 7 MB) |
| NIDRM Region 4 (8.5" x 11") (PDF, 8 MB) |
| NIDRM Region 5 (8.5" x 11") (PDF, 6 MB) |
| NIDRM Region 6 (8.5" x 11") (PDF, 7 MB) |
| NIDRM Region 8 (8.5" x 11") (PDF, 7 MB) |
| NIDRM Region 9 (8.5" x 11") (PDF, 6 MB) |
GIS Data for the 2024 National Insect and Disease Risk Map
Data includes a zip file with downloadable GIS raster data (geotiff format)
*Please keep your web browser window open and allow extra time when downloading large zip files.
| CONTIGUOUS US | PREVIEW |
|---|---|
| Composite hazard from all pests (ZIP) | .XLS File 13 KB |
The 2024 composite risk layer is also available as a map service.
Since 2012, significant tree mortality events from fire, forest pest outbreaks, and broad scale forest harvesting operations have reduced or in some cases eliminated hazard. For the 2018 NIDRM update, we adjusted the composite 2012 NIDRM by subtracting major disturbance events, thus accounting for reductions in hazard due to previous and ongoing tree mortality. The update does not account for increases in hazard due to tree growth, which can make additional trees susceptible and vulnerable to new forest pest attacks. Also, the update does not account for new pests on the landscape such as the Flathead fir borer, a wood boring beetle that primarily attacks stressed or weakened Douglas-fir, true firs, and western larch in Region 6.
The 2018 NIDRM update was generated by removing areas at risk if they experienced significant mortality according to data from the USDA Forest Service, Forest Health Protection (Insect and Disease Survey database); and the University of Maryland (Dr. Matt Hansen - Global Forest Change dataset).
NIDRM WITH AREAS OF INTEREST (2018 UPDATE)
| NIDRM 2018 POSTERS AND PLACEMATS (COMPOSITE MAPS) |
|---|
| Conterminous U.S. with Areas of Interest Poster (2' x 3') (PDF, 26 MB) |
| Alaska & Hawaii with Areas of Interest Poster (2' x 3') (PDF, 16 MB) |
| Conterminous U.S. with Areas of Interest (8.5" x 11") (PDF, 8 MB) |
| Alaska & Hawaii with Areas of Interest (8.5" x 11") (PDF, 4 MB) |
| Conterminous U.S. Poster (2' x 3') (PDF, 2 MB) |
| Alaska and Hawaii Poster (2' x 3') (PDF, 17.5 MB) |
| Conterminous U.S. (8.5" x 11") (PDF, 3.1 MB) |
| Alaska and Hawaii (8.5" x 11") (PDF, 3.8 MB) |
GIS Data Downloads
Downloadable Zip files for each state include:
GIS raster data (Geotiff format)
Metadata for raster (MS Excel format)
Tabular summaries by county (MS Excel format)
| STATE |
|---|
| Conterminous U.S. GIS Data (10 MB ZIP) |
|
| NIDRM 2012 REPORT FILES |
|---|
| Executive Summary (2 MB PDF) |
| Full Report (Print Ready) (51 MB PDF) |
| Full Report (Spread) (51 MB PDF) |
| Report-Only (Spread) (18 MB PDF) |
| Atlas-only (Spread) (36 MB PDF) |
| NIDRM 2012 POSTERS AND PLACEMATS |
| Composite Map Poster (2' x 3') (10.5 MB PDF) |
| Subwatersheds Map Poster (2' x 3') (10.8 MB PDF) |
| Composite Map (8.5" x 11") (3.1 MB PDF) |
| Subwatersheds Map (8.5" x 11") (3.8 MB PDF) |
| KEY REFERENCES |
| NIDRM 2006 Report (20 MB PDF) |
| Multi-Criteria Framework for Producing Local, Regional, and National Insect and Disease Risk Maps (978 KB PDF) |
GIS Data for the 2012 National Insect & Disease Risk Map Report
Data includes:
Zip files with downloadable GIS raster data (ArcINFO GRID format)
Information on how to access 2012 NIDRM map and image services
Downloadable tabular summaries (MS Excel format)
Within each zip file* is an ArcINFO workspace that includes the relevant raster data (GRID format), a README file that explains the file naming conventions, and layer files for default symbolization. Each raster dataset includes embedded metadata. The Data Dictionary describes these datasets.
*Please keep your web browser window open and allow extra time when downloading large zip files.
| CONTIGUOUS US | PREVIEW |
|---|---|
| Hazard by agent-Eastern pests (ZIP) | .XLS File 32 KB |
| Hazard by agent-Western pests (ZIP) | .XLS File 32 KB |
| Hazard by agent - Pests that span L48 (ZIP) | .XLS File 32 KB |
| Composite hazard from all pests (ZIP) | .XLS File 13 KB |
| Hazard by host tree species (ZIP) | .XLS File 36 KB |
| Treed area, Total basal area (ZIP) | .XLS File 13 KB |
| ALASKA | PREVIEW |
| All NIDRM GIS raster datasets (ZIP) | .XLS File 50 KB |
| HAWAII | PREVIEW |
| All NIDRM GIS raster datasets (ZIP) | .XLS File 25 KB |
Map Services
Map services provide web layers with fixed symbology that are convenient for map display but not usable for geo-processing. NIDRM hazard by agent map services can be added to your GIS maps by making an ArcGIS server connection to https://imagery.geoplatform.gov/iipp/rest/services/Forest_Management and navigating to the appropriate folder.
These map services are combined with tables, graphics and text in the Forest Health Advisory System (FHAS). Use this web map application to explore forest health hazards in places of interest such as National Forests and Parks, Tribal Lands, and more.
Tabular Data Downloads
186 individual forest pest : individual tree species host models were created by forest health experts to build the 2013- 2027 NIDRM outputs. For details on how each of these 186 models were parameterized please download the 2013-2027 NIDRM Model Details workbook.
Excel workbooks that summarize NIDRM 2013 – 2027 outputs by National Forests and National Parks: National Forest Summaries and National Park Summaries
Watershed Summaries
The following downloads are ArcGIS 10.1 file geodatabases that summarize NIDRM 2013-2027 outputs by 6th level (12-digit) Hydrologic Unit Code (HUC) watersheds. The geodatabase tables summarize composite hazard, as well as breakouts by individual insect or disease and by host tree species that can be joined to the included 6th level HUC watershed polygons Note: This summary is based on a 2010 version of the 6th level HUC watershed dataset and tables will not properly join to more recent 6th level HUC versions.
| CONTIGUOUS US | PREVIEW |
|---|---|
| Geodatabase with HUC 12 polygons (ZIP) | .XLSX File 55 KB |
| ALASKA | PREVIEW (Excel Files) |
| Geodatabase with HUC 12 polygons (ZIP) | .XLSX File 54 KB |
| HAWAII | PREVIEW (Excel Files) |
| Geodatabase with HUC 12 polygons (ZIP) | .XLSX File 32 KB |
| CONTIGUOUS US & ALASKA | PREVIEW (Excel Files) |
| NFS Subwatersheds (Excel File) | .XLSX File 14 KB |